NOTE: THIS IS NOT A COMPLEX WALKTHROUGH/GUIDE. JUST A FIELD JOURNAL.
Mini-walkthrough - try to get some Mayan (green, slowdown) and possibly Hindu (gold, bigger loot chance) totems. Then go for the Bat'leth (8x0, 1x20). With some Mayan totems and a bit of practice it's the best weapon in the game. I used it the whole time from 4th floor onwards.
You can find totems in golden treasure chests in a special category.
Since I've found every single piece of loot and fought every kind of monster during my gameplay, I decided to post a commented field journal for other players - mainly because of unclear equipment stats when looting (particularly of the special weapons).
The journal is complete (as of 2016/05/01), with all 111 entries, their Witch-level and Damage/Armor/Block values (for weapons, armor and shields respectively).
Use it without hesitation if you have any use of it. My pleasure.
Though, please, don't just copy it and claim it as your own. (Almost) everything else is allowed.
Should you have a question or find a typo/mistake/anything else you'd like to point out, please, feel free to comment/ask/correct me.
PS: If you want to be sure that I'll answer you, mention (@helpo1) me.